1. Field of the Invention
The present invention relates generally to the prevention of infectious disease, and more specifically, to compositions comprising multivalent hybrid polypeptides having immunogenic M protein and Spa peptides capable of eliciting protective immunity.
2. Description of the Related Art
Group A streptococcal pharyngitis is one of the most common bacterial infections in school-age children. In addition to streptococcal pharyngitis, there may be associated nonsuppurative sequela, such as acute rheumatic fever (ARF). Although the incidence of ARF has declined in developed countries, the disease remains rampant in developing countries (Community prevention and control of cardiovascular diseases. Report of a WHO expert committee. World Health Organization. 1986:732). Another form of streptococcal infection is invasive, which afflicts thousands of children and adults each year, often resulting in death or significant morbidity (Stevens, J. Infect. Dis. 2:S366, 1999). Efforts to develop a vaccine that would prevent group A streptococcal infections have been ongoing for over eight decades (Dochez et al., J. Exp. Med. 30:179, 1919; Lancefield, J. Exp. Med. 47:91, 1928).
Hence, a need exists for identifying and developing compositions therapeutically effective against streptococcal infections, particularly those compositions that can function as a vaccine and elicit protective immunity. Furthermore, there is a need for vaccine formulations that can be varied to protect against or treatment for infection by different streptococcal serotypes. The present invention meets such needs, and further provides other related advantages.